Fuse



March 18, 1.924. 1,487,040

nnunnuu-nuy J, A. THAKE ET AL FUSE Filed March 25 1922 Patented Mar. 18, 1924.

UNITED STATES 1,487,040 PATENT OFFICE.

JOHN A. TEAKE AND CHRISTIAN H. TORI, OF BROOKLYN, NEW YORK.

FUSE.

Application filed March 25 To all whom it may concern:

Be it known that we, Jon A. TI-IAKE and ()nins'rniiv .l'I. TORI, citizens of the United States, and residents of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Fuses, of which the followin is a specification.

ur invention relates to fuses and particularly to a renewable plug fuse.

It has recently been the custom in the art to form plug fuses with a window so that the condition of the fusible element might be readily determined. In the one-time fuses when the fusible element becomes ruptured, the plug is unscrewed from the fuse socket and discarded. In the renewable fuse only the fusible element is replaced.

In constructing plug fuses the fusible element or link is confined within a chamber which prevents the blowing of the fuse from starting fire. In the majority of fuse plugs now manufactured this chamber is of such proportions with relation to the amount of gas which may be generated by volatilizetion of the fuse link, as to permit a concus sion of such magnitude as to, in many instances, mutilate the fuse boxes and in other ways prove disastrous. Means for successfully eliminating this concussion has been that of introducing into the chamber, packing substances of various sorts. While this practice effectively reduced the probability of disastrous concussion, it necessarily *in creased the cost of manufacture of the fuses, and in many Ways proved unsatisfactory and inefiicient.

It is therefore an'object of our invention to provide a fuse plug in which the chamber containing the fusible element is restricted and in which the magnitude of the fusible element is restricted to a proportionally greater extent-so as to greatly reduce concussion when the fuse is burned or blown. he reduction of the size of the chamber is accomplished by positioning the mica window approximately centrally of the fuse body and the particular construction makes it possible at the same time to reduce the amount of metal in the fuse link to a proportionally greater extent.

Our invention further contemplates the provision of a structure wherein the fuse may be renewed so that only a portion of the fuse need be replaced when the fuse has been blown by short circuit or overload. In

1922. Serial No. 546,692.

this connection, our invention contemplates a structure wherein a renewable fuse composed of a small number of parts is provided thereby enabling the manufacture of renewable fuses as cheaply and in many instances, more cheaply, than the one-time fuse.

The features of construction of our improved invention as well as the advantages incident thereto will be made more apparent in the accompanying specification and drawings wherein one illustrative example thereof is described and illustrated. In the drawings:

Fig. 1 is a longitudinal section through a fuse plug constructed in accordance with our invention.

Fig. 2 is a separated perspective view.

Fig. 3 is a side elevation of the fuse parts, separated, partly in section, and,

Fig. 4; is an end view of the fuse plug.

Referring now more particularly to the drawings wherein like reference characters indicate like parts, the numeral 10 indicates the fuse body which is preferably made of porcelain and which has securely aflixed thereto and forming a part thereof the standard screw shell ll. The body 10 is formed with a central recess 12 which may be of any desired size and shape but is here shown as a tapering recess extending from the outerface of the body 10 to the rear thereof. The porcelain portion of the body 10 is stopped abruptly to form an annular shoulder 13 for a purpose to be more fully hereinafter set forth. I

ScreW-threadedly engaging the shell portion 11 of the body is a fuse element container 14 formed preferably with an extension 15 whereby the same may be rotated for screwing it into and out of the shell 11. This container 14 carries the fusible link or element 16, one end of which extends over to the outer cylindrical surface of the container is as indicated at 17 while the outer end thereof is connected to contact element 18. The container or member 14 is recessed centrally thereof as at 19, this recess forming a continuation of the recess 12 formed in the body 10.

In fuse plugs now universally employed, the chamber or recess of the fuse extends approximately the whole length and approximates in size the combined recesses 12 and 19 of this present construction.

However, in conformity with our invention we propose to restrict the fusible element chamber by positioning approximately centrally of the fuse body the mica window 20. This mica window is inserted from the open end of the shell 11 and bears against the annular shoulder 13 formed by the end of the body 10. Therefore, when the fuse element container 14: is screwed into the open end of the shell, its inner end bears against the mica window 20 and holds the same in place. Thus, a restricted fusible element containing chamber 21 is provided. together with a fusible element which is restricted to a proportionally greater extent. which reduces to a large extent the concussion produced when the fuse is burned or blown on short circuit.

Obviously the condition of the fusible link in may be readily determined its condition may be observed through the rcce s 12 in the body 10. Furthermore, it is obvious that the required standard size of the fuse is maintained at the same time providing-a link of restricted size and a stricted air chamber in which the fusible link is disposed and without the provision of packing substances or the like.

In referring to the simplicity of construction of our impro ed plug fuse it should be noted that the fuse requires broadly but three parts. namely, the body 10. the standard screw shell 11 andthe fusible element container 14. This material reduction of parts enables the manufacture of these plug fuses more cheaply than the majority of the fuses now in use. either the onetime or renewable type. The fuse element container l-I may, when the fuse is burned or blown. be removed and replaced by a new one. Furtherfore, should the mica window 20 be come clouded or mutilated, this may be easily removed and replaced.

From the foregoing it will be immediately obvious that we have provided a fuse capable of more etlicient results and furthermore, a renewable fuse which can be made cheaper than the fuse known as the one-time fuse.

lVhile a fuse constructed in accordance with the details of construction shown here in as prove-n e'flicient we do not wish to be unnecessarily limited in this respect. but reser e the right to make such changes and modifications as may come within the pun view of the accompairi'ing claims.

Haring thus described our invention. what we claim is:

I. In a renewable fuse plug a recessed. body, a removable fuse element container and a partitioning clement dis )oscd intermediate said body and forming with said container a relatively evicted air chamber in which the fusibh ,enient is enclosed.

2. In a renewable ping fuse a recessed body. a fuse element container i'einoi'ably secured to said body and provided with a recess contiguous to the of said body and a transp rent me be positioned intermediate said body 5 forming a restricted air chamber in which the fusible element is enclosed.

3. In a fuse of the ciass described a contrally recessed body, a fuse element container removably secured to said body. said container being formed with a recci-1s comniunicat-ing with the recess of said body, a fuse element in said container and a transparent partitioning member disposed intermediate the lcngth of said fuse body and forming with said fuse element container a restricted air chamber in which the fusible element is enclosed.

at. In a renewable fuse plug. a recessed body provided with a screw she ll. a recessed fuse element container screw-threadedlv engaging said body. the recesses of said body and fuse element container forming a continuous chamber and a transparent partitioning member disposed intermediate said chamber and forming a restricted air chamber in which said fusible element is enclosed, said partitioning member being removable and held in place by said fuse element container.

JOHN A. THAKE. CHRISTIAN H. TOBP. 

